Magneto



Dec. 2, 1924. 1,517,997

T. G. LOUIS MAGNETO Filed May 26, 1922 v 3 Sheets-Sheet 1 Dec. 1924-1,517,997

- T. G. LOUIS MAGNETO Filed May 26, 1922 3 Sheets-Sheet 2 INVENTORTTORNEYS Dec. 2, 1,517,997

T. G. LOUIS MAGNETO Filed May 26, 1922 5 Sheets-Sheet 5 a INVENTORATTORNEYS 40 at properly timed intervals.

Patented Dec. 2, 1924.

UNITED STATES PATENT OFFICE.

TERBENGE G. tours, or SPRINGFIELD, massacnusnr'rs, ASSIGNOR '10 wIcoELECTRIC oomrm, A ooaronflrion or massaonnsmrs.

MAGNETO.

v Applfcation filed May 26', 1922. Serial No, 563,911.,

To all whom it may concern:

Be it known that I, TERRENCE G. LOUIS, a citizen of the United States,residing at Springfield, in the county of Hampden and I State ofMassachusetts, have invented new and useful Improvements in Magnetos, ofwhich the following is a specification.

This invention relates to magnetos and moreparticularly to improvementsin magnetos of the type wherein-the armature moves into and out ofcontact with magnetic poles.

The invention has for one object to provide, in a magneto of the generaltype described, an improved means foroperating the armature.

The invention has. for another object to provide in a magneto, armatureoperating means including an oscillatory lever, the

2 movement of which controls the time of generation of current, andmeans for varying the time of current generation-by varying the distancebetween the fulcrum of said lever and the point of application of powerthereto;

Another object of the invention is to provide in a magneto of the classdescribed, an armature which is mounted for rocking movement toward andaway from its poles,

:0 and means for operating 1t independently of engine speeds.

Another object of the invention is toprovide in a magneto having apivoted armature movable into and out of contact with as magnetic poles,means automatically operable when released for moving the armaturethrough one complete cycle of movement, and means adapted for operationfroman engine for releasing the first named means Another object of theinvention is to providein a magneto of the type described, a casingwithin which all'the working parts of the magneto'are supported andcontained,

including its armature and operating and timing mechanism therefor.

Other objects and advantages will appear in the following descriptionand in the illustrative embodiment of the invention in the accompanyingdrawings, in which- Fig. 1 is a front elevational view of. a'

magneto embodying the inventiou, the cover.

magneto on, and driving it from an engine;

and

Figs. 6 and 7 are front elevational views of laminations employed inbuilding up a part of the magnetic field structure.

Referring to these drawings, the magneto comprises a suitable frame orcasing, a source of magnetic flux, cores or pole pieces for the sourceforming part of a magnetic circuit therefrom, a suitable generatingwinding or coils associated with one or both of the cores, an armaturemovable. into and out of contact with the pole pieces to cooperatetherewith in producing a magnetic circuit of alternately low andrelatively high reluctance from the source, and operatlng mechanism formoving the armature preferably including timing means to vary the timeat which the armature leaves the poles. .The frame of the magneto may bevariously constructed, as desired, but preferably is in the form of acasing to enclose and protect the working parts of the magneto. Thecomplete casing, comprising a back 10 and cover 11, is shownin Fig. 5and the back 10, which supports all the workin 1 parts of the magneto isshown in full detafi in Figs. 1 and 3L The back 10, as disclosed herein,is of non-magnetic material. The source of magnetic flux, preferablyalthough not necessarily, consists of one or more permanent magnets, andas disclosed herein, consists of two series of bar magnets 12 arrangedside by side, the magnets of each series being preferably superposedonev upon another in vertically stacked. relation. The ends of likepolarity of all the magnets, of the unit magnetic source thus afforded,

are received within substantially U-shaped surfaces of the U-shapedrecess, so as to make notonly a good magnetic connection between themagnets and clips but also an adequate mechanical connection to hold themagnets in place.

The magnetic circuit from the source includes two cores 14, or polepieces, which are arranged in spaced parallel relation. Followingpreferred practice, these cores are made up of soft iron laminations,one of which is shown at in Fig. (3. A feature of novelty, however,consists in the formation of the clips 13 as integral parts of the corelaminations 15, the latter having upper extensions 16 for thispurpose'as shown in Fig. (i. The unit magnetic source is, however, widerthan the cores and accordingly the holding clips 13, as afforded by thegrouped extensions 16, should be broadened out and made coextensive inwidth with the-1.,

source. This result is effected by supplementary laminations 17, of theform shown in Fig. 7, a plurality of which are placed on each side ofeach core, as hown in Fig. 3. The clip forming extensions 16 and thelaminations 17 have holes 18 to receive rivets 19, by which thelaminations, forming the clips 13, are held firmly together and are alsoprovided with holes. 20 to receive screws 21, whereby the clips aresecured to back 10,. as best shown in Fig. 3. Preferably, a bar 22 ofnon-magnetic material bridges across and mechanically connects the twoclips 13 at their lower portions and the screws 21 are applied throughthis bar, which is clamped against the front face of the clips 13. Thelatter, being clamped to back 10, adequately support the upper ends ofcores 14 and the laminations 15 are provided with holes 24 to receivescrews 25 which clamp the laminations of the core together and hold itto back 10. These screws 25 pass through a bar 26 of non-magneticmaterial, which bridges across and mechanically connects the front facesof the cores 14 at their lower ends, and through a spacing sleeve 27inserted between the core and back.

The generating winding is preferably applied to each of the cores 14 andbetween the bars 22 and 26. Preferably, this winding comprises two coils28 and 29 on each' core, the former being a primary and the latter asecondary winding. The electrical connections of the coils of the twowindings have not been shown, as they are well understood in the art andare not essential to an understanding of the invention. A fulldisclosure of one suitable way in which the coils may be connected andthe electrical circuits, of which they form a part, is given in U. S.Letters Patent No. 1,307,342 granted June 24, 1919 to Phelps Brown. Forthe present purposes, it will suffice to state that the coils 29 are themain generating winding and the coils 28 are provided for a choking plcs ol the magnetic source.

function in resisting and retarding the diminution of flux in cores 14so long as the circuit in which they are included is closed. The openingand closing of such circuit is controlled by an interrupter mechanism,which includes fixed and movable breaker points 30 and 31 respectively.is mounted in a casing 32 secured in bar 26 and the latter is slidablein this casing and moved upwardly by a member 33 through theintermediary of a spring 34 and downwardly by the engagement of thismember with abutnients 35 on a rod 36, which is fixed to the movablebreaker point and slides in member 33.

Cooperating with the lower ends of cores 14- is an armature 38, which ismovable into and out of contactwith, and serves to magnctically connectsuch ends, which form the \Vhen in contact with the poles, a magneticcircuit of very low reluctance is established through cores 14 from themagnetic source and, when moved away from this source, the reluctance ofthe circuit is very materially increased, thereby causing a change influx through the generating winding and the production of a currenttherein. This armature is made up of laminations in the usual manner andthe interrupter operating member 33 is fixed thereto. Since the abutment35 is spaced below member 33, when armature 38 is in contact with itspoles, the breaker points 30 and 31 will not be opened until thearmature has moved some distance away from its poles and the chokingfunction of the coils 28 is thus availed of to hold the flux in cores 14until the armature has acquired considerable speed, at which time thebreaker points open and a rapid rate of change offlux in cores 14 ensuesto cause the production of a high voltage in coils 29.

The armature 38, according to this invention, is supported for swingingmovement to and from its poles, and while this can be accomplished invarious ways, it is preferred to accomplish it in the following manner.The'back 10 is provided near its lower end with axially spaced andaxially alined hubs 39, one on each side of the back, leaving aconsiderable space between them and behind the armature. Fixed in thesehubs 39 are bearing bushings 40. These bushings extend beyond the innerends of hubs 40 sufiiciently to receive, and pi vot'allv support ontheir exteriors, rocker arms 41 which are connected at their free endsin laterally spaced relation to armature 38 by screws 42, the latteralso serving to clamp the member 33 to the armature.

The driving mechanism for moving the armature away from its poles willnext be described. Such mechanism-includes an oscillatable lever 44which. is pivoted at one end on a fulcrum 45 and is located at the Theformer rear of the armature and substantially centrally thereof.Adjacent this lever is a driving arm 46 which is clamped to a drivingshaft 47 by a screw 48 passing through the split hub thereof. The shaft47 is rotatably mounted in one of the bushings 40 and extends beyond thelatter outside the magneto casing to receive an operating lever 49. Thearm 46 has fixed therein a 'crankpin 50 which projects laterallytherefrom and is pivotally received in the lever a point intermediatethe ends of the latter. Interposed between the lever 44 and the armatureis a driving spring 51 which functions to drive the armature. downwardlyaway from cores 14, after the magnetic hold between the latter and thearmature has been broken--the force of spring 51 being in this instanceinsufficient to overpower the opposing force of magnetic attractionwhich is at its maximum value due to contact of the armature and poles.A suitable spring seat is formed on lever 44 to position spring 51 and aspring seat 52 is provided on the armature 38', which seat 52 has anupward. extension 53 constituting an abutment and adapted to be engagedwith an abutment on lever 44 after the latter has moved downwardly to acertain distance. To adjust for this distance and to vary it, as andwhen desired, the abutment on lever 44 takes the form of a set screw 54,which is threaded in the lever and held in adjusted position by a locknut 55.

For restoring the armature and reseating it on its poles, or bringing itclosely enough thereto to enable the magnetic attraction of the poles toeffect the seating, suitable resilient means are provided having atendency to lift the armature. As shown, such means comprise a doubletorsion spring 56, having one pair of its arms secured to the lever 44,as by the screw 57, and having its other pair of its armsbearing-upwardly against the under face of armature 38.

For the purpose of conveniently varying the time at which the lever 44will act to dislodge the armature by engagement of the abutments 53 and54, means are provided for shifting the fulcrum 45 of lever 44 andthereby varying thethrow of the latter or the location of the throw orboth. To this end, the fulcrum 45 is fixed eccentrically to the end of atiming shaft 58 which is mounted in the other bushin 40 and extendsoutside the magneto caslng to receive an operating lever 59 (Fig. 1).Adjacent lever 59 and fixed to the member 10 of the magnet casing is aquadrant plate 60 against one face of which a surface 61 of the leverengages. Slidably mounted in lever 59 is aspring pressed member 62 whichhas awedge shaped end to bear against the other face of the quadrant 60and thus bind the lever thereto and hold it in the various positions ofadjustment which it may assume. 7

By turning lever 59, the-throw of lever 44 is varied by the movement ofits fulcrum toward or away from the point ofpower application, being thecrankpin 50. Also by moving lever 59, the location, in which the throwof lever 44 occurs, is varied, for the fulcrum not only has a componentof movement'toward and away from pin 50 along the center line of lever49 but also a component of movement at right angles to such line,thereby moving abutment 54 toward or away from its cooperating abutment53. The magneto is operated by oscillating shaft 47 through a suitablearc of travel and this oscillation may be accomplished in any suitableway, even manually by swinging the lever 49. The shaft 47 may beautomatically oscillated from an internal combustion engine in variousways which will readily occur to those skilled in the art. As an exampleof one of many suit'able ways, reference is made to Fig. 5, wherein themagneto casing is shown as supported from the frame A of an enginethrough the intermediary of a bracket 5 and the free end of lever 49 isivotally connected to an ec-v centric straps, operated by an eccentrice, which has a suitable throw and is fixed to the engine cam shaft 0.

Assuming that engine A is of the four cycle type, shaft 47 makes onecomplete oscillation for each cycle of operation of the engine andstarts to move in a counterclockwise direction (as viewed in Figs. 3 and5) as the piston of the engine moves into position for the charge to befired. Such movement of shaft 47 causes lever 44 to swing downwardly andthe first result of such movement is to compress the driving spring 51and place it under the proper stress for the armature driving function.In this particular case, the driving spring 51, even when fullystressed, has not suiticient force to dislodge the armature, whichremains held to its poles by magnetic attraction until the abutments 53and 54 enga e, at which time the armature is pushed fr In its poles by.a force acting through rigid and non-elastic means. On a very slightseparation of the armature and poles, the opposing force'due to magneticattraction is very greatly diminished and continues to diminish withextreme rapidity as the arma- I ture moves 'lstill farther away.Consequently, the driving spring 51 very soon exerts a force superior tothat due. to magnetic attraction and the armature soon acquiresconsiderable speed. When the desired speed is attained, the breakerpoints 30 and 31 are opened to release the flux in the magnetic circuitand cause the desired rapid change of flux for the generation of theignition current. Thereafter, the lever "44 starts its return or upwardtravel and 5 plish this purpose.

spring 56 lifts the armature toward its poles. either in itselfefiiecting the reseating of the armature or moving the lattersufficiently into the magnetic field to accom- 1 terially diminished anon an upward movement of the lever, the restoring spring is tensionedwhile the lever moves back to prevent any considerable opposition by thedriving spring to the armature lifting op- 1 c ration.

The time, when the ignition spark is produced, is controlled by the timeat which the abutments 53 and 54 engage and by .manipulation of lever59, the spark may be retarded or advanced within a fairly wide .range oflimits as desired. It is also possible by movement of lever 59 to adjustthe apparatus so that the abutments 53 and 54 will not engage so that,when desired, the

2 magneto may be cut out of operation in a very simple manner withoutdisturbing its drivlng connections with the engine.

The invention has been disclosed herein,

in an embodiment at present preferred, for illustrative purposes, butthe scope of the invention is defined by the appended claims rather thanby the foregoing description.

Vhat I claim is 1. In a magneto, of the type wherein an armature movesinto and out of engagement with magnetic poles, means for seating thearmature on its poles, driving means for moving thearmature away fromits poles after the magnetic hold on the latter has 4 been broken, andan oscillatory lever movable relatively to the armature and operableperiodically to break the magnetic hold on the armature.

2. In a magneto, of the type wherein an armature moves into and out ofengagement with magnetic poles, means for seating the armature on itspoles, driving means for moving the armature away from its polesafterthe magnetic hold on the latter has been broken, an oscillatorylever movable relatively to the armature and operable peri- -odically tobreak the magnetic hold on the armature, and means for varying'the throwof said lever. to vary the time at. which the driving means is allowedto act.

3. In amagneto, of the type wherein an armature moves into and out ofengagement with magnetic poles, means for seating the armature on itspoles, driving means for moving the armature away from its poles afterthe magnetic hold on the latter has been broken, and mechanism operableperiodically to break the magnetic hold on the armature and :allow thedriving means to act, said mechanism comprising a driving .arm having afixed degree of oscillation the latter has been broken, and an oscilla-'tory lever operable periodically to break the n'iagnetic hold on thearmature and at the same time diminish the force exerted by saidresilient means on the armature.

5. In a magneto, of the type wherein an armature moves into and out ofengagement with magnetic poles, means for seating the armature on itspoles, resilient driving means for moving the armature away from itspoles after the magnetic hold on the latter has been broken and anoscillatory lever movable relatively to the armature and operable on onestroke to first increase the force of said driving means on the armatureand then to break the magnetic hold on the armature.

6. In a magneto, of the type wherein an armature moves into and out ofengagement with magnetic poles, means for seating the armature on itspoles, resilient driving means for moving the armature away from itspoles'aiter the magnetic hold on the latter has been broken, and anoscillatory lever movable relatively to the armature and operable on onestroke to break the magnetic hold on the armature and on the otherstroke to diminish the tension of said driving means.

7. In a magneto, of the type wherein an armature moves into and out ofengagement with magnetic poles, a frame, means pivotally supporting thearmature therein for swinging movement to and from its poles, a levermounted in said frame for oscillation toward and away from the armature,means for oscillating the lever, a driving spring interposed between thelever an the armature, and means interposed between the lever andarmature to provide a rigid non-elastic connection therebetween afterthe lever has moved toward the armature a predetermined degree.

8. In a magneto, of the type wherein an armature moves into and out ofengagement with magnetic poles, a frame, means pivotally supporting thearmature therein for swinging movementto and from its poles, a levermounted in said frame for oscillation toward and away from the armature,means for oscillating the lever, a spring interposed betweenthe leverand the arms.- ture, and non-elastic means interposed between the leverand armature and adapted -to be engaged with each on one stroke ofsubstantial alinement with the driving shaft.

and having an eccentric portion, a driving arm fixed to the drivingshaft and carrying a crank pin, a lever pivotally connected intermediateits ends to the crank pin and fulcrumed on said eccentric portion at oneend, the other end of 'said lever adapted when moved in one direction tocause the armature to leave its poles and when moved in the otherdirection to permit the armature to be reseated on its poles, and meansfor effecting the reseating of the armature.

10. In a magneto, having an armature movable into and out of contactwith magnetic poles, operating mec anisxn therefor comprising, anoscillating drive shaft mounted adjacent and parallel with thecomprising,

armature; a lever ivoted at one end and oscillatable by said shaft, andresilient means interposed between the other endof said lever and thearmature.

11, In a magneto, having an armaturemovable into and out of contact withmagnetic poles, operating mechanism therefor an oscillating drive sh'aftinounted adjacent and parallel with the armature, a lever pivoted at oneend'and oscillatable; by said shaft, resilientmeans interposed betweenthe other endof said lever and the armature, and means for varying havinthe throw of said lever.

12. In a magneto, having an armature 'movable into and out of contactwith magnetic poles, comprising,

operating mechanism therefor an -osc1llating drive shaft mountedadjacent and parallel with thearmature, a driving arm on said shaft acrank-pin, a lever pivotally connecte intermediate its ends to saidcrank pin, an adjustable fulcrum on which said ever is pivoted at oneend, and resilient means interposed between the other end of said leverand the armature.

13. In a magneto, a frame, a source of magnetic flux and magnetic polepieces therefor mounted on sai frame, a generatingwinding provided onthe, pole pieces,

an armature pivotally' mounted on said frame and adapted'to periodicallyswing into contact with and connect said pole ieces, a drive shaftsupported by the we and on one side of the and behind the armature'foroperating the ture in parallel relation with the latter,

driving mechanism located betweeri' the armature and frame and operablefrom said shaft to, love the armature, a timing shaft mounted inalin'cment with the drive shaft and disposed on the opposite side of theframe, and means operably connecting the timing shaft and said mechanismto control the time at which the latter is, effective to move thearmature.

let. In a magneto, a casing including a back and a cover thereforcooperating there:

) with to afford a substantially closed housing,

a source of magnetic flux and "magnetic poles therefor mounted on theinner face of said back, an armature to connect and disconnect said polepieces, means rigidly connected to the armature and extendingrearwardlyto and pivoted on said back, a i drive shaft mounted on the latter inthe rear of the armature and extending through one wall of the casing, atiming shaft similarly mounted and in alinement with the driving shaftand extending through the opposite side of the casing, means associatedwith the timingshaft and located outside ,the casing for moving it toand holding it in various positions of regular adjustment, means on thedrive shaft and located outside the casing for operating the latter,mechanism located between said shafts and inside the casing for operatinthe armature from the drive shaft, an means similarly located andoperated from the timing shaft for varyin the time of operation of saidarmature rom saidlast named mechanism. 15. In a magneto, a frame, asource of magnetic flux and magnetic pole pieces therefor mounted onsaid frame, a generating winding provided on the pole pieces, anarmature adapted to periodically connect said pole pieces, alinedbearings rovided on opposite sides of said frame an in back of saidarmature, arocker arm fulcrumed on the exterior portion of each bearing,both of said arms being fixed to said armature, whereby the latter issupported for swinging movement, a drive shaft'mounted' in one bearingand a timing shaft mounted in the other bearing, both shafts projectinbeyond both ends of their bearings and eac having a part projectingoutside the casing,- mechanism located between, the bearings latter fromthe drive shaft, and means similarly located and operated from, thetiming shaft for varying the time of operation of the-armature by saidmechanism.

In testimony whereof I- have aflixed my 125 signature.

Tani-inner e. LOUIS.

